The present invention relates to drill bit assemblies, specifically drill bit assemblies for use in subterranean drilling. More particularly the present invention relates to drill bits that include engaging members that degrade the formation through shear and/or compressive forces.
U.S. Pat. No. 7,270,196 to Hall, which is herein incorporated by reference for all that it contains, discloses a drill bit assembly comprising a body portion intermediate a shank portion and a working portion. The working portion has at least one cutting element. The body portion has at least a portion of a reactive jackleg apparatus which has a chamber at least partially disposed within the body portion and a shaft movable disposed within the chamber, the shaft having at least a proximal end and a distal end. The chamber also has an opening proximate the working portion of the assembly.
Also, U.S. Pat. No. 5,038,873 to Jürgens, which is herein incorporated by reference for all that it contains, discloses a drill tool including a retractable pilot drilling unit driven by a fluid operated motor, the motor comprising a stator mounted on the interior of a tubular outer housing and a rotor mounted on the exterior of a tubular inner housing axially supported in said outer housing and rotationally free with respect thereto. The pilot drilling unit is rotationally fixed within the inner housing, but axially moveable therewithin so that pressure of drilling fluid used to drive the motor will also act on reaction surfaces of the pilot drilling unit to urge it axially forward. The top of the pilot drilling unit includes a fishing head for retracting the pilot drilling unit from the drilling tool, and reinserting it therein.